Science Times: Bioresorbable Silicon Electronic Sensors for the Brain

Invasive intracranial monitoring is a frequently performed procedure that aids clinical management of critically ill patients, although it is associated with potential infection, hemorrhage, and other risks. A recent article in Nature described a novel bioresorbable electronic sensor platform that successfully monitors many clinically useful parameters, including intracranial pressure (ICP) and temperature (ICT), and demonstrated that its performance is comparable to that of commercially available tools, with the added benefit of being bioresorbable.1

Each bioresorbable sensor is composed of a silicon nanomembrane (or related sensor material) resting on a surface of poly(lactic-co-glycolic acid) (PLGA). It is covered by silicon oxide that acts as electric insulation and a fluid barrier (Figure, A). The sensor and its coverings are fixed onto either nanoporous silicon or magnesium foil, providing structural support. The air cavity in the structural substrate provides structural compressibility, required to monitor pressure (Figure, A). The entire sensor platform measures 1 × 2 × 0.08 mm (Figure, B). An alternative sensor platform was also created with dimensions of 3 × 6 × 0.11 mm to illustrate successful fabrication scaling for other potential uses. Additional simple modifications enable monitoring of parameters such as pressure, acceleration, temperature, flow rate, thermal conductivity, and pH. In each of these cases, the performance of these bioresorbable sensors was noninferior to that of commercially available sensors in vitro.